1. Field of the Invention
The present invention relates to a sensor system for monitoring surroundings on a mechanical component, and further relates to a method for applying control to, and for evaluating, a sensor system according to the present invention.
2. Description of the Related Art
Published German patent application document DE 10 2009 029 021 A1 (which is not considered a prior art) discloses a sensor system, which is attachable to surfaces of machines or machine parts, and which has at least one sensor element made up of a layered structure of flexible electrically conductive and electrically insulating plies. The proximity and/or contact of a body or an object can be measured using such a sensor system, for example in order to stop the operation of an assembly robot having a sensor system.
It is furthermore known per se that for automatic proximity detection and/or collision detection, monitoring of the surroundings of the machine is performed using different sensor principles and sensors, for example optical sensors, ultrasonic sensors, or capacitive sensors, for example including contact-force sensing via the piezoelectric effect. Such sensors can as a rule be used in special cases, for example, in order to monitor machine parts having simple shapes and defined movement paths, so that upon detection of the proximity of a person, for example, reliable deceleration of the drive systems or processing equipment of the machine can be initiated.
If the hazardous machine part has a surface of relatively complex shape or a complex trajectory, on the one hand uninterrupted sensor-based surroundings monitoring is often possible only with a great deal of outlay or in some cases not at all. For example, optical sensing can be impeded by shadowing at edges and undercuts of the machine surface, or integration of sensors can also be impossible for lack of installation space.
For safe operation of machines it is usual, in order to meet safety standards, to utilize safety devices having two mutually independent safety channels with a diagnostic function, so that a single error in the system does not result in loss of safety. Failure of a safety channel is reliably detected and reported, while the second safety channel maintains the safety function. Dual sensor-based monitoring, embodied independently, is necessary for such applications. Sensors for safe configuration of machines having two safety channels that are flexibly adaptable to complexly shaped surfaces are not known.
Also known, from published utility model document DE 20 2005 002 475 U1, is a foamed-material cover, embodied especially to be used for collision detection with industrial robots, that is equipped with proximity-detecting, tactile, and capacitive sensors. Attachment of such an assemblage to different industrial robots is, however, often laborious.